In wireless communications systems, a stream of media, such as voice, video, data, picture, includes some undesirable silence periods that cause end-to-end media communication latency. Such silence frames include initial silence frames appearing ahead of the first actual media frame as well as silence frames that appear between successive media frames. To reduce call set-up and media-delivery latency, it is desirable to minimize such silence periods.
For example, a class of wireless services intended for quick, efficient, one-to-one or one-to-many (group) communication has existed in various forms for many years. In general, these services have been half-duplex, where a user presses a “push-to-talk” (PTT) button on a phone/radio to initiate a group call. If granted the floor, the talker then generally speaks for a few seconds. After the talker releases the PTT button, other users may request the floor. These services have traditionally been used in applications where one person, a “dispatcher,” needs to communicate with a group of people, such as field service personnel or construction site workers, which is where the “dispatch” name for the service comes from. A key feature of these services is the desirability of quick call set up and media delivery.
There is a need, therefore, for mechanisms to reduce end-to-end media communication latency.